Power tool including an output position sensor

Abstract

A power tool including a motor and an impact mechanism. The impact mechanism is coupled to the motor and includes a hammer driven by the motor, and an anvil positioned at a nose of the power tool, and configured to receive an impact from the hammer. The power tool also includes a sensor assembly positioned at the nose of the power tool, and an electronic processor. The sensor assembly includes an output position sensor configured to generate an output signal indicative of a position of the hammer or the anvil. The electronic processor is coupled to the output position sensor and to the motor, and is configured to operate the motor based on the output signal from the output position sensor.

What is claimed is: 
     
       1. A power tool comprising:
 a motor including a rotor and a stator; 
 an impact mechanism coupled to the motor, the impact mechanism including
 a hammer driven by the motor, and 
 an anvil positioned at a nose of the power tool, the anvil configured to receive an impact from the hammer; 
 
 an impact case housing the anvil and the hammer; 
 a central axis about which at least one of the group consisting of the rotor, the hammer, the anvil, and combinations thereof is configured to rotate; 
 a motor sensor board positioned perpendicularly with respect to the central axis, the motor sensor board extending in a radial outward direction with respect to the central axis; 
 a sensor assembly mounted to a top surface of a circuit board and located within a recess below a first plane located below the rotor, the first plane extending parallel to the central axis in a front-rear direction and horizontally outward through sides of the power tool in a left-right direction, a second plane formed by the top surface of the circuit board being parallel with the central axis and intersecting the motor sensor board, the sensor assembly configured to generate an output signal indicative of the hammer impacting the anvil; and 
 a controller including a processor and a memory, the controller connected to the sensor assembly and to the motor, the controller configured to:
 receive the output signal from the sensor assembly, 
 detect a number of impacts executed by the hammer based on the output signal from the sensor assembly, and 
 control the motor based on the number of impacts executed by the hammer. 
 
 
     
     
       2. The power tool of  claim 1 , wherein the sensor assembly is positioned in the radial outward direction between the rotor of the motor and a trigger. 
     
     
       3. The power tool of  claim 1 , wherein the controller is configured to stop driving the motor after a predetermined number of impacts have been executed by the hammer. 
     
     
       4. The power tool of  claim 1 , wherein the sensor assembly is located in front of the motor in the front-rear direction that is parallel to the central axis. 
     
     
       5. The power tool of  claim 1 , wherein at least a portion of the sensor assembly is located below at least a portion of the hammer in the radial outward direction. 
     
     
       6. The power tool of  claim 1 , further comprising a transmission coupled between the motor and the impact mechanism, the transmission positioned in front of the motor sensor board along the central axis and positioned above the sensor assembly in the radial outward direction. 
     
     
       7. The power tool of  claim 1 , wherein the power tool is powered by a rechargeable battery pack. 
     
     
       8. The power tool of  claim 1 , wherein the controller is configured to control the motor based on the number of impacts executed by the hammer by:
 receiving, from an external device, a type of fastener to be fastened by the power tool; 
 controlling, based on the type of fastener, the motor based on the number of impacts executed by the hammer. 
 
     
     
       9. The power tool of  claim 8 , wherein the controller is configured to:
 determine that a desired torque output of the power tool has been reached based on the number of impacts executed by the hammer, wherein the desired torque output is based at least partially on the type of fastener; and 
 control the motor to stop operating in response to determining that the desired torque output of the power tool has been reached. 
 
     
     
       10. A power tool system comprising:
 a power tool including
 a motor including a rotor and a stator, 
 an impact mechanism coupled to the motor, the impact mechanism including
 a hammer driven by the motor, and 
 an anvil positioned at a nose of the power tool, the anvil configured to receive an impact from the hammer, 
 
 an impact case housing the anvil and the hammer, 
 a central axis about which at least one of the group consisting of the rotor, the hammer, the anvil, and combinations thereof is configured to rotate, 
 a motor sensor board positioned perpendicularly with respect to the central axis, the motor sensor board extending in a radial outward direction with respect to the central axis, 
 a sensor assembly mounted to a top surface of a circuit board and located within a recess below a first plane located below the rotor, the first plane extending parallel to the central axis in a front-rear direction and horizontally outward through sides of the power tool in a left-right direction, a second plane formed by the top surface of the circuit board being parallel with the central axis and intersecting the motor sensor board, the sensor assembly configured to generate an output signal indicative of the hammer impacting the anvil; and 
 
 an external device configured to communicatively couple to the power tool; and 
 a controller including a processor and a memory, the controller configured to:
 detect a number of impacts executed by the hammer based on the output signal from the sensor assembly, and 
 control the motor based on the number of impacts executed by the hammer. 
 
 
     
     
       11. The power tool system of  claim 10 , wherein the power tool includes the controller. 
     
     
       12. The power tool system of  claim 10 , wherein the external device is configured to communicatively couple to the power tool via a wired interface. 
     
     
       13. The power tool of  claim 10 , wherein the controller is configured to control the motor based on the number of impacts executed by the hammer by:
 receiving, based on a user input received via a user interface of the external device, a type of fastener to be fastened by the power tool; 
 controlling, based on the type of fastener, the motor based on the number of impacts executed by the hammer. 
 
     
     
       14. The power tool of  claim 13 , wherein the controller is configured to:
 determine that a desired torque output of the power tool has been reached based on the number of impacts executed by the hammer, wherein the desired torque output is based at least partially on the type of fastener; and 
 control the motor to stop operating in response to determining that the desired torque output of the power tool has been reached. 
 
     
     
       15. The power tool of  claim 10 , wherein the sensor assembly is positioned in the radial outward direction between the rotor of the motor and a trigger; and
 wherein the motor sensor board includes a Hall Effect sensor. 
 
     
     
       16. A power tool system comprising:
 a power tool including
 a motor including a rotor and a stator, 
 an impact mechanism coupled to the motor, the impact mechanism including
 a hammer driven by the motor, and 
 an anvil positioned at a nose of the power tool, the anvil configured to receive an impact from the hammer, 
 
 an impact case housing the anvil and the hammer, 
 a central axis about which at least one of the group consisting of the rotor, the hammer, the anvil, and combinations thereof is configured to rotate, 
 a motor sensor board extending in a radial outward direction with respect to the central axis, 
 a sensor assembly mounted to a top surface of a circuit board and located within a recess below a first plane located below the rotor, the first plane extending parallel to the central axis in a front-rear direction and horizontally outward through sides of the power tool in a left-right direction, a second plane formed by the top surface of the circuit board being parallel with the central axis and intersecting the motor sensor board, the sensor assembly configured to generate an output signal indicative of the hammer impacting the anvil; and 
 
 an external device configured to communicatively couple to the power tool, wherein the external device is configured to determine a type of fastener to be fastened by the power tool; and 
 a controller including a processor and a memory, the controller configured to:
 detect a number of impacts executed by the hammer based on the output signal from the sensor assembly, 
 control, based on the type of fastener, the motor based on the number of impacts executed by the hammer. 
 
 
     
     
       17. The power tool system of  claim 16 , wherein the power tool includes the controller. 
     
     
       18. The power tool system of  claim 16 , wherein the external device is configured to communicatively couple to the power tool via a wired interface. 
     
     
       19. The power tool system of  claim 16 , wherein the external device includes a user interface, and wherein the external device is configured to determine the type of fastener by receiving a user input, via the user interface, that indicates the type of fastener. 
     
     
       20. The power tool of  claim 19 , wherein the controller is configured to:
 determine that a desired torque output of the power tool has been reached based on the number of impacts executed by the hammer, wherein the desired torque output is based at least partially on the type of fastener; and 
 control the motor to stop operating in response to determining that the desired torque output of the power tool has been reached.